The present invention relates generally to an aircraft vertical speed indicator (VSI), and more specifically to computerized VSI adapted to be inserted into an existing VSI instrument panel opening and providing added functionality to a pilot without the need to replace critical instruments or perform instrument panel modification.
The form factor of a standard VSI is referred to in the industry as a standard 3-inch round instrument, the instrument having a 3-inch round bezel that protrudes through the instrument panel into which the VSI is inserted, three mounting screws, a round glass faceplate protecting the needle assembly, and a “dog-leg” protrusion located on the lower left of the instrument face. This dog-leg area is used to locate a calibration adjustment (typically in the form of a slotted screw head) that is used to bias out needle errors and is used specifically with the VSI instrument and the altimeter. The remainder of the VSI instrument is typically located behind the instrument panel, and is of varying sizes and shapes.
A VSI is typically located in the “standard six” instrument cluster. This cluster is a grouping of six instruments, organized as three instruments across and two instruments high. The “standard six” instrument cluster is typically positioned in front of the pilot or co-pilot of an aircraft. A VSI traditionally resides in the lower right position within this standard instrument cluster, which puts it virtually directly in front of the pilot and biased slightly downward and to the right. The instrument panel space directly in front of the pilot, and including this instrument cluster, is referred to as being within the “primary instrument scan” of the pilot. This space is of especially high value while operating the aircraft as it requires little or no head movement to monitor the information presented.
A VSI instrument is unique in that it is one of the lowest criticality instruments residing within the standard six instrument cluster. More importantly, for traditional small-piston aircraft that make up the most populous segment of the domestic aircraft fleet, it is not a required instrument by regulation. Criticality refers to the safety implications if the instrument fails or provides incorrect information. If the VSI fails in any manner, the pilot reverts to the obvious and independent source of altitude information that is displayed on the adjacent altimeter. As such, the rate information provided by the VSI is used simply as a convenient method to control and monitor rates, while the altitude is the important piece of information that affects aircraft safety.
The low criticality, wide spread use, and non-required nature of the VSI instrument makes it a unique candidate for improvement. The present invention takes advantage of these unique characteristics and provides augmented functionality in a novel manner within the VSI form factor.